Process and apparatus for the production of lead oxid



H. S. REED AND H. L. PUBLOW.

PROCESS AND APPARATUS FOR THE PRODUCTION OF LEAD OXID.

APPLICATION FILED SEPTLII. 920.

1,376,581 Patented May 3, 1921.

FIGURE l. FIGURE 2;

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UNITED STATES PATENT. OFFICE.

EAJRRY s. REED AND HENRY PUBLOW, or EAST LANSING, MICHIGAN.

. PROCESS AND APPARATUS FOR THE PRODUCTION OF LEAD OXID.

Specification of Letters Patent.

Application: filed September 17, 1920. Serial "No. 411,013.

Ingham, and State of Michi an, have invent ed certain new and useful mprovements 1n.

Processes and Apparatus for the Production specification.

of Lead Oxid, of which the following is. a

production of lead oxid from basic carbonates of lead containing organic matter or admixed with organic matter, and the apparatus for carrying out suchprocess.

The invention is of particular consequence in the lead process for the recovery of sucrose from molasses. The great advantage is that it enables the'complete recovery of lead in a superior form for use in said lead process. The invention is of course of advantage or may be of advantage in other processes but is of particular advantage in the process 1ndicated.

The object of the invention is to provide an efiicient process and apparatus for the repear from the detailed description to follow.

We accomplish the objects of ouninvention by the devices and meant described in the following specification. The invention is clearly defined in the claims.

\Ve carry out the improved process by the apparatus illustrated in the accompanying,

drawing, forming a part of this specification,"

in which:

Fig. I is a longitudinal detail sectional elevation view of the improved oxidizing furnace, taken on line 1-1 of Fig. II.

Fig. II is a detail transverse sectional elevation view through the oxidizing furnace, taken on lin 22 of Fig. I.

Fig. III is a diagrammatic detail longitudinal sectional view through the disassociating furnace, taken on line ,33 of Fig. IV.

F ig, IV is a transverse detail sectional view through the disassociating furnace, taken on line '44 of Fig. III.

In the drawings the sectional views are taken looking in the direction of the little arrows at the ends of the section lines and parts throughout the several views.

Patented May '3, 1921.

Considering the numbered parts of the drawing, 1 is the shell of the oxidizing fur nace provided with a usual. construction of vertically sliding doors 2 through the center of which 1s a usual construction of testing port3. An air inlet passage 4 with a series of upwardly openinginlet's 5, 5,.5 .is in the bottom of the. furnace. I

revolv- A vent 6 is rovidedin the upper part of the furnace. This invent1on relates to a process for-the ing drum 7 is disposed longitudinally within the furnace on roller supports 8, 8, which are driven by the pulley 9.

The furnace is heated by electric heating units 10, 10 preferably disposed at each side -of the drum. Pyrometers 11, 11 are provided in the upper part of the furnace chamber, and a pyrometer 12 is located centrally in the reyolvlng drum.

The dlsassociating furnace comprises a shell 13 within which is disposed a hollow drum 14 carried on suitable rollers 15, ,15 dr ven by any suitable means fen-revolving i the same. The drum 14 1s slightlyincline'd f to advancethe contents through the furnace as the drum is slowly rotated. "Electric heating units 16 are disposed entirely around the central part of the drum l4 and partition plates 17 and 17 are at each end of the heating units to retain and conserve the heat.

A hopper 19 with spout 2O deliveringinto the drum 14 is at the mtake end of thisrfurnace, and a receiving bin 21 is at the opposite end to receive the treated material. outlet 22 is provided forcollecting'the carbonic dioxid that is developed by the process, conserving the same for use particularly in the lead process above referred to. This furnace is provided with a pyrometer 23 centrally disposed within the hollow drum 14.

In carrying out our improved process we first dry the mass containing the basic carbonates of lead and organic material and then pulverize it so that the mass willpass through a ten mesh sieve. The same could be somewhat finer or coarser. However, fine particles'are likely to be wasted by being blown away as dust and coarse particles are more difiicult tohandle in subsequent operations. A charge of the granular mass contaming the dried basic carbonates of lead is then introduced into the mixing drum 7 of i the oxidizing furnace. slow rotation to tumble the mass over. The furnace is maintained regularly at a temperature of about 600 degress'Fahr. The introduction of the cold tumbling barrel and This is kept in a 7 its contents drops the'temperature which is above that temperature the tendency is to.

the reduction to metallic lead by the organic matter. The range of temperature which secures the best result is from about 400 de- 10 grees to 600 degrees Fahr. f The air containing the oxygen moves very slowly through the furnace, it not being necessary to provide a stack or any other means of forced draft.

"The time consumed in the process for the treatment of this material in the lead process above referred to is about 45 minutes when using the apparatus shown. The material is tested by taking a spoonful and subjecting it to a temperature above that necessary for the disassociating of the basic carbonate of lead; This step of'the process is considered complete if no metallic lead appears when thus tested.

When this step of the process is complete, as indicated above, the charge is withdrawn and the treated material is passed to the disassociating furnace illustrated in Figs. III and IV. The charge is introduced into the hopper 19 filling the same quite full so that it acts as a plug-to prevent escape of the contained gases within the furnace. The material discharges through the spout 20 either by being poked by hand or by a suit-able conveyer, not illustrated, into the revolving 85 drum 14. It is here subjected to a temperature of fronrllOO degrees to 1200 degrees Fahr. The temperature should not exceed a temperature slightly below the fusing point of lead oxid (PbO), that is, approxi- 40 mately 1600 degrees F ahr. This is to avoid fusing the contents of the furnace into an unwieldly mass.

The basic carbonates of lead by this treatment are decomposed into the lead oxid (PbO) and carbonic acid gas (CO and water (H O). The carbonic acid gas is collected at the port 22. In the lead process above referred to it is passed to the carbonation tanks and used with or without any intermediate storing. v

The interior of this furnace is filled with highly heated inert carbonic acid gas as soon as the operation is in full progress. This is ofadvantage in the disassociating step of the process. This protects the parts from undue corrosion as well. v

The material, in pas ing through the drum 14, is thus completely disassociated. The lead oxid is discharged into the collectin bin 21. v

Tlaving thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. The process for producing lead oxid from basic carbonates of lead containing or admixed with organic matter consisting in drying the mass, reducing the same to granular form, introducing the mass into arevolving drum in a vented electric furnace, agitating and heating the same in the presence of the contained air to a temperature of about 600 degrees-Fahr. to slowly oxidize the organic matter, until a test portion heated above the disassociating temperature of the basic carbonate of lead shows no reductlon to metallic lead, introducing the treated mass into a closed electric furnace having a discharge opening for the carbonic acld gas and having a revolving drum for advancing and agitating the contents, and a collecting bin for the lead oxid, and heating the same to a temperature of 1100 degrees to 1200 degrees F ahr. whereby the mass of material is heated within an atmosphere of carbon dioxid, whereby the material is disassociated into lead oxid (PbO), in granular 03m, carbonic acid gas and water, as speci- -2. The process for producing lead oxid from basic carbonates of lead containing or admixed with organic matter consisting in drying the mass, reducing the same to granular form, agitating and heating the same in a vented electric furnace in the presence of the contained air to a temperature of about 600 degrees Fahr. to slowly oxidize the orgame matter, until a test portion heated above the disassociating temperature of the basic carbonate of lead shows no reduction to metallic lead, introducing the treated mass into a closed electric furnace having a discharge opening for the carbonic acid gas and having a revolving drum for advanclng and agitating the contents, and a collecting bin for the lead oxid, and heating the same to a temperature of 1100 degrees to 1200 degrees Fahr. whereby the mass of material is heated within an atmosphere of carbon dioxid, -whereby the material is disassociated into lead 'OXlCl (PbO), in granular form, carbonic acid gas and water, as specified.

3. The process for producing lead oxid from basic carbonates of lead containing or admixed with organic. matter consisting in drying the mass. reducing the same to granular form, agitating and heating the same in a vented electric, furnace in the presence of the contained air to a temperature of about 600 degrees F ahr. to slowly oxidize the organic matter, until 'ia test portion heated above the disassociating temperature of the basic carbonate of lead shows no reduction to metallic lead, introducing the treated mass into a closed electric furnace having a discharge opening for the carbonic acid gas, and agitating and heating the same to a temperature of 1100 'degrees to 1200 degrees Fahr. whereby the mass of material is heated within an atmosphere of carbon dioxid,

whereby the material is disasso'ciated into 7 mass into a closed electric furnace having a discharge opening for the carbonic acid gas, and heating the same to a temperature of 1100 degrees to 1200 degrees Fahr. whereby the'mass of material 'isheated within an atmosphere of carbon dioxid, whereby the material is disasso'ciated into lead oxid (PbO), in granular form, carbonic acid gas and water, as'specified. Y

5. The process for producing lead oxid from basic carbonates of leadcontaining or admixed with organic'matter consisting in drying the mass, reducing the same to granular form, agitating and heating thesame in a vented electricfurnace inrthe presence of the contained air to a temperature of about 600 degrees Fahr. to slowly oxidize the or- -ganic matter, until a .test portion heated above the d-isassociating temperature of the basic carbonate of lead shows no reduction to metallic lead, introducing the treated mass into a closed electric furnace having a discharge opening for 'the carbonic acid gas, and agitating and heating the same to a temperature of 1100 degrees to 1200 degreesFahri, whereby the material is disassociated into lead oxid (PbO), in granular forlm, carbonic acid gas and ,water, as specifiec. I

admixed with organic-matter consisting in drying the mass, reducing the same to granular form, introducing the mass 1I1l10- a revolving drum in a vented electric furnace,

agitating and heating the same in the presence of the contained air toa temperature-of about 600 degrees F ahr. to slowly oxidize the organic matter, until a test portion heated above thehdisassociating temperature of the basic carbonate of lead shows no reduction .to metallic lead,and heating the treated mass to a temperature of 1100 degrees to 1200,de-

grees Fahn, whereby the material is disas sociated into lead oxid (PbO), in granular form, carbonic acid gas and water, as

8. .The process for producing lead oxid from basic carbcmates of lead containing or admixed with organic matter consisting in.

drying the mass, reducing the same to .g'ran a vented electric furnace in thepresen'ce of ular form, agitating and heating thesarn in' the contained air to a temperature of about 600 degrees Fiahr; to slowly oxidize the or.-

ga-nic matter,f' until a test portion heated above the disassociating temperature of the basic carbonate of lead shows no reduction to metallic lead, and heating the treated mass to a temperature of 1100 degrees to 1200 degrees Fahr., whereby the material is dis associated into lead oxid (PbO), in granu-I lar form, carbonic acid gas and Water, as specified.

9. The process for producing lead o'xid (PbO) from basic' carbonates of lead containing or admixed with organic matter consisting in reducing the same to granular form, agitating the same in a vented electric furnace and heating the same in the presence of the contained air to slowly oxidize the organic matter until the same is substantially eliminated, introducing the treated mass into a closed electric furnace having a discharge opening for the carbonic acid gas,

6. The process for producing lead oxid and heating the same sufliciently to disassofrom basic carbonates of lead containing or admixed withorganic matter consisting in drying the mass, reducing the same to granular form, agitating and heating the same in a vented electric furnace in the presence of the contained air to a temperature of about 600, degrees Fahr. to slowly oxidize the organic matter, until a test portion heated above thedisassociating temperature of the basic carbonate of lead shows no re duction 'to inetallic lead, introducing the treated mass into a closed electric furnace having a dischargeopening for-the carbonic n n l basic ciate the mass into lead oxid (PbO), carbonic acid gas (CO and water (H 0),

without raisingjhe temperature sufficiently to fuse the said lead oXi-d; 10. The .process for producing lead oxid (PbO) from basic carbonates of lead containing or admixed with organic matter consisting in reducing the same to granular form, agitating the same in a vented electric furnace and heating the same. in the presence of the contained air to slowly oxidize the organic matter untilthe same is substantially eliminated, introducing the treated mass into a closed electric furnace havinga discharge opening for the carbonicacid gas,

and heating the same sufiiciently to disassociatethe mass into lead oxid (PbO bonic acidgas (6G and water 5 11. ris roc ss producing ls oxid (D (N 7 ,1 cu, lrom basic carbonates of lean can? taining or admixed with organic matter cons'isting in reducing the same to granular form, agitating the same in a vented electric furnace and heating the same in the presence of the contained air to slowly oxidize the organic matter until the same is substantially eliminated, then heating the same sufiiciently to disassociate the mass into lead oxid (PbO), carbonic acid gas (CO and water (H O), without raising the temperature sufficiently to fuse the said lead oxid.

12. The process for producing lead oxid (PbO) from basic carbonates of lead containing or admixed with organic matter consisting in. reducing the same to granular form, agitating the same in a vented electric furnace and heating the same in the presence of the containedair to slowly oxidize the organic matter until the same is substantially eliminated, then heating the same sufii ciently to disassociate the mass into lead oxid (PbO), carbonic acid gas (CO and water (H O).

-13. The process (PbO) from basic carbonates of lead confor producing lea-d oxid taining or admixed with organic matter consisting in heating the same in the presence of the contained air to slowly oxidize the organic matter until the same is substantially eliminated, then heating the same sufliciently to disassociate the, mass into lead oxid (PbO), carbonic acid gas (CO and water (H 0).

14. An apparatus for treating basic carbonates of lead containing or admixed with organic matter, comprising a Vented electric furnace, with a revolving drum therein, a closed electric furnace having a port for collecting the carbon dioXid gas, with an inclined revolving drum therein, with hopper'delivering into one-end of said drum, and a bin for collecting the lead oxid.

In witness whereof, we have hereunto set our hands and seals in the presence of two witnesses.

HARRY S. REED. HENRY L. PUBLOW. 

